A Dynamic Analysis And Numerical Simulation Of Cylindrical Spur Gear And Crack Fault

Gear transmission is used most extensively in mechanical transmission. The gear will be taken place crack fault,fracture,vibration,and so on. When it is bearing load and transferring power. Therefore, it is necessary to research and analysis the behavior of kinematics and dynamics for gear system. In this paper, a three-dimensional parametric model of a cylindrical spur gear is established based on Pro/E. The parametric model is imported into ADAMS (Automatic Dynamic Analysis of Mechanical Systems), and then the virtual prototype is built in ADAMS. The characteristic curves of rotational speed and meshing force are obtained by simulation. The theoretic guidance will be provided for the dynamic optimization by the analysis.With the development of industry and modern science technology, higher request on load-carry capacity of gear transmission system has been put forward, in which the contact strength is an important criterion. At the same time, Finite Element Method (FEM) was used widely in the analysis of gear transmission intensity. In this paper, using the interface technology between Pro/E and ANSYS software, the simulation analysis of stress status of the involute cylindrical spur gear, designed in Pro/E, under a certain load is made. The research results has reference value to gear model library development and to the optimization design of the gear.With the improve of reliability and safety of mechanical system, more and more people have paid attention to researching the mechanical element and fault diagnosis.In this paper,the 3-dimensional FEM dynamic model of a cracked gear structure is established,the dynamic characteristics, i.e., the natural frequency, the deformed shape and so on,due to crack of gear tooth are analyzed in this paper.The influence of crack position and crack depth etc. on dynamic characteristics of gear is investigated by using computer simulation and the FEM.It shows that the influence of crack depth and crack position on both natural frequency and deformed shape of gear is significant.The natural frequency drops and deformed shape changes when a crack started.This natural frequency drops with the increase of crack depth, but the influence of crack position on both natural frequency and deformed shape is greater than that of the crack depth. The natural frequency of gear drops more when crack locate at the tooth root in comparison with that of the gear when crack appears at the pitch circle.When a crack starts, the mode pattern of gear structure becomes very different from that of gear without crack.When a crack starts, the amplitude is augmented and the dynamic stress of gear changes in the crack neighborhood. The theoretical basis will be provided for the gear crack fault analysis by these conclusions effectively, and it has certain practical value for the research on fault mechanism of mechanical transmission system.